Reports suggest negligence behind deadly DuPont accident

New information on a deadly pesticide plant accident seems to support the need to reassess how safety regulations at chemical facilities are managed.

Last November, four workers at DuPont’s La Porte, Texas, facility were killed by exposure to methyl mercaptan — a toxic gas.

Although an investigation by the U.S. Chemical Safety Board (CSB) is ongoing, initial findings from the independent federal agency indicate a pattern of negligence. According to CSB testimony submitted for a joint Senate committee hearing in December, maintenance workers at the plant routinely had to open pipes which vented the poisonous gas, in order to drain liquids from the waste line. It was “typically drained directly into the work area inside the building, rather than into a closed system,” and workers did not use personal protective equipment such as respirators. In addition, the agency states that the building’s ventilation fans — which could have reduced the concentration of the gas — were not in service, although workers had been issuing complaints for months.

Details which surfaced earlier this month indicate the problems persisted for years rather than months. According to an article published in the Houston Chronicle, public records show DuPont reported emission and ventilation problems to the Texas Commission on Environmental Quality (TCEQ) as early as 2008 — with plant managers stating that as much as three pounds of methyl mercaptan can leak out in an hour during maintenance work. Given that rate, the newspaper calculated that the plant’s poorly ventilated rooms could reach 600 parts per million within an hour. The chemical is considered deadly for humans at levels over 1,000 ppm. For comparison, Occupational Safety and Health Administration (OSHA) guidelines say workers should not be exposed to an average of more than 10 ppm per day.

In addition, the newspaper found that the state regulatory agency, TCEQ, cited the facility 51 times since 2009, for violations including emissions breaches. Yet TCEQ never notified OSHA to prompt an investigation.

In the CSB testimony, chairman Rafael Moure-Eraso points to this “patchwork of U.S. safety standards and guidance for such facilities” as an area in desperate need of reform, and notes the grim déjà vu nature of the accident. Since 2010, this is the third deadly incident that the CSB has investigated involving the release of toxic chemicals at a DuPont facility. In two additional cases, there were no fatalities.